<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>设置左边框的宽度</title>
</head>

<body>

    <head>
        <style>
            p {
                border-style: solid;
                border-left-width: 15px;
            }
        </style>
    </head>
    <p><b>注释：</b>如果单独使用，"border-left-width" 属性不起作用。请首先使用 "border-style" 属性来设置边框。</p>
</body>


</html>